CPT symmetry

CPT symmetry is the invariance of physical laws under the combined transformations of charge conjugation, parity inversion, and time reversal. It is a fundamental result of local, Lorentz-invariant quantum field theory.

CPT theorem: A theorem stating that local, Lorentz-invariant quantum field theories with a Hermitian Hamiltonian are invariant under combined charge conjugation, parity, and time reversal. It formalizes why the combined transformation remains a symmetry under standard quantum-field-theory assumptions.
Antiparticle: A particle with the same mass as its corresponding particle and opposite values for its additive charges. CPT maps a particle state to a corresponding antiparticle state while reversing space and time.
CP violation: A difference between physical processes and their charge-conjugate, parity-inverted counterparts. Weak interactions violate CP even though the combined CPT symmetry remains intact.
Standard-Model Extension: An effective field theory that parameterizes possible violations of Lorentz and CPT symmetry while retaining the Standard Model’s fields. It provides a systematic framework for describing and comparing possible CPT-violating effects.
Charge conjugation: A transformation that replaces particles with their antiparticles and reverses their additive internal charges. It supplies the charge-reversal part of the combined CPT operation.
Particle–antiparticle mass equality: The equality of the masses of a particle and its corresponding antiparticle, required by CPT symmetry. This is one of the experimentally testable consequences of CPT invariance.
Parity violation: A failure of physical processes to remain unchanged under spatial inversion. Its discovery showed that one component of CPT need not be a symmetry on its own.
Neutral-meson oscillation: The quantum mixing of a neutral meson with its antiparticle, producing time-dependent changes in their identity. Oscillation measurements can reveal differences between particle and antiparticle behavior relevant to CPT tests.
Parity transformation: A spatial inversion that maps each position vector to its negative, reversing handedness. It supplies the spatial inversion included in CPT.
Particle–antiparticle lifetime equality: The equality of the total lifetimes of a particle and its corresponding antiparticle implied by CPT symmetry. CPT requires matching total decay rates for corresponding particle and antiparticle states.

Linked from 15 pages